Gaskets provide a mechanical seal that fills the space between two mating surfaces. They may be provided to prevent leakage from or into the pieces under compression. Gaskets typically can allow less than perfect mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced from cutting sheet materials, such as gasket paper, rubber, silicon, metal, cork, felt, neoprene, nitrile rubber, fiberglass or plastic polymer, such as polychloro, trifloro ethylene.
Pre-cured polyurethane and antenna gaskets have been provided with aluminum skeletal carrier die cut to fit the workpiece, such as an aircraft antenna. The polyurethane provides an effective environmental sealant. It also demonstrates excellent cohesion after installation and provides a high degree of environmental protection, still allowing for easy removal of the workpiece.
Polyurethane provides a non-hazardous seal with no silicon oil residue before, during or after installation or removal. Moreover, polyurethane is not problematic with paint adhesion or preparation and there is no peripheral silicon contamination. Polyurethane provides a positive moisture barrier for easy workpiece removal and provides noise and vibration dampening.
In some applications, however, some polyurethane may creep under compression creating an overrun outside the gasket area. This may sometimes require manual removal.